Yes - you can literally buy a completed BCM lower assembly and a completed BCM upper assembly...sit the upper on the lower and push two take-down pins and have a completed rifle without: A) having to "build" anything, B) having to pay FET (Federal Excise Tax - which is required on firearms shipped from the manufacturer as "complete").
BCM also sells complete rifles now, but why pay the FET?
If you settle on a BCM - you will never be disappointed.